System and method for retrieving information from disparate information sources and integrating the information in accordance with a domain model

ABSTRACT

A system and method are provided for retrieving and integrating information from different information sources. The system includes a model agent and a plurality of integration agents. A query is sent to a first integration agent, which assigns the query to any of the plurality of integration agents. The first integration agent creates one or more query results by integrating the information obtained from the information sources through at least one of the plurality of integration agents in a peer-to-peer fashion.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates generally to accessing information and, more particularly, to retrieving information from disparate information sources and integrating the retrieved information in a user-defined format.

[0003] 2. Description of the Related Art

[0004] We live in an information age. More information is being created and made available than ever before, due to the development of computers in general and access technologies in particular. For example, the Internet provides an unprecedented amount of information. However, there are problems to be solved. First, the information sought is normally stored in a distributed manner. For example, a single information source may store only a portion of the information sought and therefore other information sources may have to be separately accessed to gather the information sought. Second, even if the information sought is successfully located in one or more information sources, the information may not be readily available to a user for various reasons. For example, the portions of the information stored in different information sources may be in different formats such that the portions are not readily combinable without additional efforts on the part of the user. Third, using a single, centralized integration system to retrieve information from a number of different information sources and integrate the retrieved information may be impractical as the number of the information sources grows. Also, such a centralized integration system requires storing data in a data warehouse first and then fetch the data from the data warehouse, thereby providing possibly outdated data.

[0005] Therefore, there is a need for a system and method for retrieving information directly from disparate information sources without going through a data warehouse and integrating the retrieved information in a user-defined format. There is also a need for a system and method for retrieving and integrating such information in real-time without resorting to a single, centralized integration system.

SUMMARY OF THE INVENTION

[0006] A system and method are provided for retrieving information from one or more information sources in response to a query and integrating the information in accordance with a domain model. The query is based upon the domain model. The system is based upon a computer network having one or more computer systems in communication with one another. The system includes a model agent and a plurality of integration agents. The model agent has access to the domain model. The plurality of integration agents has access to the one or more information sources. A first integration agent receives the query and processes the query through at least one of the plurality of integration agents. The first integration agent then integrates information obtained from the plurality of integration agents and creates one or more query results.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0008]FIG. 1A is a block diagram illustrating an information system according to the present invention;

[0009]FIG. 1B is a block diagram illustrating the information system of FIG. 1A further including a security agent;

[0010]FIG. 2 is a block diagram illustrating an expanded information system according to the present invention; and

[0011]FIG. 3 is a flow diagram illustrating the operation of the information system according to the present invention.

DETAILED DESCRIPTION

[0012] In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known elements have been illustrated in schematic or block diagram form in order not to obscure the present invention in unnecessary detail.

[0013] It is further noted that, unless indicated otherwise, all functions described herein may be performed in either hardware or software, or some combination thereof. In a preferred embodiment, however, the functions are performed by a processor such as a computer or an electronic data processor in accordance with code such as computer program code, software, and/or integrated circuits that are coded to perform such functions, unless indicated otherwise.

[0014] In FIG. 1A, a reference numeral 100 generally designates an information system according to the present invention. The information system 100 includes a user interface 102, model agent 104, a first integration agent 106, and a second integration agent 108. The user interface 102 is in communication with the model agent 104 through a communication link 110. The user interface 102 is also in communication with the first integration agent 106 and the second integration agent 108 through communication links 112 and 114, respectively. The model agent 104 is in communication with the first integration agent 106 and the second integration agent 108 through communication links 116 and 118, respectively. The first integration agent 106 is in communication with the second integration agent 108 through a communication link 120.

[0015] The user interface 102 is a software program installed in a user computer system (not shown). Specifically, the user interface 102 collectively represents all interface programs between a user (not shown) of the information system 100 and various software agents such as the model agent 104 and the first and second integration agents 106 and 108. Specifically, the user interface 102 includes a client browser layer 102A (e.g., a web browser), a communications layer 102B (e.g., TCP/IP), an Internet web server layer 102C (e.g., IIS, Apache, NES, etc), a query layer 102D (e.g., ColdFusion), and an agent translator layer 102E (e.g., ColdFusion custom tags).

[0016] The model agent 104, the first integration agent 106, and the second integration agent 108 are role-based software agents. Preferably, the model agent 104, the first integration agent 106, and the second integration agent 108 are installed in the user computer system. Alternatively, the model agent 104, the first integration agent 106, and the second integration agent 108 are installed in any of computer systems (not shown) in a network (not shown) including the user computer system. The network may have either wired or wireless connections between the computer systems. That is, the communication links 110, 112, 114, 116, 118, and 120 each are based upon either a wired physical link or a wireless physical link. For example, the user computer system having the user interface 102 may be a laptop computer or a handheld computer such as a personal digital assistant (PDA), whereas the other computer systems having such software agents may be connected through wired links (not shown). In this example, the communication links 110, 112, and 114 are based upon wireless physical links, whereas the communication links 116, 118, and 120 are based upon wired physical links.

[0017] The model agent 104 has access to a domain model 122 through a communication link 124. Preferably, the model agent 104 is installed in a computer system (not shown) that has access to a storage device (not shown) such as a hard disk, a floppy disk, CD-ROM, and RAM. The storage device may be either internal or external to the computer system. In this case, the communication link 124 includes a data bus (not shown) connecting the computer system and the storage device. Alternatively, the model agent 104 is installed in a computer system (not shown) that is connected to another computer system (not shown) having access to such a storage device. In both of these configurations, the storage device contains the domain model 122. Preferably, the computer system supports Java platform.

[0018] The first integration agent 106 has access to a first information source 126 through a communication link 128. Similarly, the second integration agent 108 has access to a second information source 130 through a communication link 132. The first and second information sources 126 and 130 each contain structured data and/or unstructured data. Optionally, the information system 100 can have one or more additional integration agents (not shown) depending on the network configuration of the information system 100.

[0019] Preferably, the user interface 102 maintains a copy of the domain model received from the model agent 104, and the user interface 102 receives model updates from the model agent 104 through the communication link 110. For example, the user interface 102 maintains a listener (not shown) that listens for model updates from the model agent 104. This way, the user interface 102 maintains a current domain model in real-time, as the integration agents 106 and 108 publishes model updates to the model agent 104.

[0020] The first and second integration agents 106 and 108 publish publication information (not shown) to the model agent 104. The publication information includes information on which portion of the domain model 122 each of the first and second integration agents 106 and 108 has access to. The model agent 104 provides the publication information to the first and second integration agents 106 and 108 such that the first and second integration agents 106 and 108 share the publication information among themselves through the model agent 104.

[0021] The user interface 102 receives one or more user inputs (not shown), and creates a query (not shown) based upon the one or more user inputs and the domain model 122. Preferably, the domain model 122 includes a plurality of classes (not shown) and one or more relations (not shown) among the plurality of classes. In this case, each class has one or more attributes. Preferably, the one or more user inputs are used to select at least a first class. The first class has a first set of one or more attributes. The one or more user inputs are also used to assign one or more keywords to the first set of one or more attributes. Preferably, the one or more keywords include one or more query criteria (e.g., strings, integers, floating point numbers, etc.).

[0022] The user interface 102 determines which of the first and second integration agents 106 and 108 to send the query to. Preferably, this determination is based upon the publication information received from the model agent 104. For example, if the query requires a query result available from the first information source 126 in whole or in part, then the publication information provided by the first integration agent 106 indicates that the query result is available from the first information source 126. Thus, the user interface 102 determines that the query should be sent to the first integration agent 106 in order to access the first information source 126. Alternatively, a user may specify a particular integration agent to which the query is initially sent.

[0023] Assuming that the query is initially sent to the first integration agent 106, the first integration agent 106 processes the query based upon the publication information provided by the model agent 104. Note that this publication information may also include the publication information from the second integration agent 108. First, the first integration agent 106 determines whether one or more sub-queries should be created from the query. If a single integration agent can fully process the query, then sub-queries need not be created from the query. For example, if the first information source 126 contains all query results corresponding to the query, then the first integration agent 106 can fully process the query without the help of the second integration agent 108. In this example, sub-queries need not be created from the query.

[0024] If, however, two or more integration agents are required to fully process the query, then sub-queries should be created from the query. For example, if the query requires first and second sub-query results, wherein the first sub-query result is available from the first information source 126 and the second sub-query result is available from the second information source 130, then the first integration agent 106 cannot fully process the query without the help of the second integration agent 108. In this case, first and second sub-queries need be created from the query. Assuming that the first and second sub-queries require the first and second sub-query results, respectively, the first sub-query should be handled by the first integration agent 106 and the second sub-query should be sent to the second integration agent 108. The first integration agent 106 processes the first sub-query and retrieves the first sub-query result from the first information source 126. Similarly, the second integration agent 108 processes the second sub-query and retrieves the second sub-query result from the second information source 130. The second integration agent 108 then sends the second sub-query result to the first integration agent 106. Subsequently, the first integration agent 106 integrates the first and second sub-query results and creates a query result corresponding to the query.

[0025] In either of these examples, the first integration agent 106 sends the query result to the user interface.

[0026] Typically, the data formats used by the first and second information sources 126 and 130 may be different than the data format of the domain model 122. Generally, the first and second integration agents 106 and 108 perform value mappings on data coming from the first and second information sources 126 and 130 (e.g., convert TEXAS to TX and vice-versa), transformations on values (e.g., converting phone numbers to different back-end formats) and function conversions (e.g., miles to kilometers and vice-versa) on values.

[0027] There are various kinds of integration agents including Java DataBase Connectivity (JDBC), document, and email integration agents. In a preferred embodiment, however, JDBC integration agent configurations are used for the first and second integration agents 106 and 108. A JDBC integration agent maps model classes and attributes to their corresponding one or more tables and columns. For example, the JDBC integration agent maps a model class to one or more structured query language (SQL) tables. These mappings can use any native SQL that can be placed in a SELECT clause and thus can concatenate fields, perform sub-strings, etc. Such a JDBC integration agent will also automatically convert between model types and back-end information source types. For example, if a given attribute is of type STRING and the information source type is a DECIMAL, the JDBC integration agent will put in the necessary logic to convert the information into a proper form. The JDBC integration agent can also combine backend tables together to form a single enterprise model class.

[0028] Although the information system 100 is shown to include only the first and second integration agents 106 and 108, additional integration agents (not shown) may be added to the information system 100 without departing from the true spirit of the present invention. Such additional integration agents will have the same interactions with other components of the information system 100 as the first and second integration agents 106 and 108 each have.

[0029] Now referring to FIG. 1B, a reference numeral 140 designates another information system including the information system 100 of FIG. 1A and a security agent 142. The security agent 142 is in communication with the user interface 102 through a communication link 144. Similarly, the security agent 142 is in communication with the first and second integration agents 106 and 108 through communication links 146 and 148, respectively. The security agent 142 is connected to a security database (not shown), which defines the users and their roles. Preferably, for each registered user, the security database contains user identification, a password, and a set of roles. The security agent 142 controls access to the roles assigned to users of the system. The roles restrict access to classes and attributes in the domain model 122 to users with the same corresponding roles. Preferably, the security agent provides the roles to the first and second integration agents 106 and 108 so that the first and second integration agents 106 and 108 evaluates the user's role(s) against requested classes and attributes in the query. If the role(s) have insufficient rights to access the requested classes and attributes specified in the query, any of the first and second integration agents 106 and 108 deny access. Alternatively, the security agent 142 evaluates each query received from the user interface 102 and evaluates the user's role(s) against requested classes and attributes in the query. If the role(s) have insufficient rights to access the requested classes and attributes specified in the query, the security agent 142 denies access.

[0030] Although the information system 140 is shown to include only the first and second integration agents 106 and 108, additional integration agents (not shown) may be added to the information system 140 without departing from the true spirit of the present invention. Such additional integration agents will have the same interactions with other components of the information system 140 as the first and second integration agents 106 and 108 each have.

[0031] Now referring to FIG. 2, an expanded information system 200 includes the information system 140 of FIG. 1 and a similar information system 201 in communication with the information system 150. Similarly to the information system 140, the information system 201 includes a user interface 202, model agent 204, a third integration agent 206, and a proxy integration agent 208. The user interface 202 is in communication with the model agent 204 through a communication link 210. The user interface 202 is also in communication with the third integration agent 206 and the proxy integration agent 208 through communication links 212 and 214, respectively. The model agent 204 is in communication with the third integration agent 206 and the proxy integration agent 208 through communication links 216 and 218, respectively. The third integration agent 206 is in communication with the proxy integration agent 208 through a communication link 220.

[0032] The user interface 202 is a software program installed in a user computer system (not shown). The model agent 204, the third integration agent 206, and the proxy integration agent 208 are role-based software agents. Preferably, the model agent 204, the third integration agent 206, and the proxy integration agent 208 are installed in the user computer system. Alternatively, the model agent 204, the third integration agent 206, and the proxy integration agent 208 are installed in any of computer systems (not shown) in a network (not shown) including the user computer system. The network may have either wired or wireless connections between the computer systems. That is, the communication links 210, 212, 214, 216, 218, and 220 each are based upon either a wired physical link or a wireless physical link. For example, the user computer system having the user interface 202 may be a laptop computer or a handheld computer such as a personal digital assistant (PDA), whereas the other computer systems having such software agents may be connected through wired links (not shown). In this example, the communication links 210, 212, and 214 are based upon wireless physical links, whereas the communication links 216, 218, and 220 are based upon wired physical links.

[0033] The model agent 204 has access to a domain model 222 through a communication link 224. Preferably, the model agent 204 is installed in a computer system (not shown) that has access to a storage device (not shown) such as a hard disk, a floppy disk, CD-ROM, and RAM. The storage device may be either internal or external to the computer system. In this case, the communication link 224 includes a data bus (not shown) connecting the computer system and the storage device. Alternatively, the model agent 204 is installed in a computer system (not shown) that is connected to another computer system (not shown) having access to such a storage device. In both of these configurations, the storage device contains the domain model 222.

[0034] The third integration agent 206 has access to a third information source 226 through a communication link 228. The proxy integration agent 208 is in communication with the model agent 104 through a communication link 230. Also, the proxy integration agent 208 has access to the first and second information sources 126 and 130 through communication links 232 and 234, respectively. The third information source 226 contains structured data and/or unstructured data. Optionally, the information system 201 can have one or more additional integration agents (not shown) depending on the network configuration of the information system 201.

[0035] The information system 201 further includes a security agent 242, which is in communication with the user interface 202 through a communication link 244. Similarly, the security agent 242 is also in communication with the third integration agent 206 and the proxy integration agent 208 through communication links 246 and 248, respectively. The security agent 242 is similarly configured to the security agent 142.

[0036] The operation of the information system 201 is generally similar to that of the information system 140 except for the operation of the proxy integration agent 208. Generally, when integration agents are used in a hierarchical approach having a regional setup (e.g., the information system 201) and a local setup (e.g., the information system 105), a proxy integration agent such as the proxy integration agent 208 is used, especially when firewalls are involved between the regional setup and the local setup. Specifically, the model agent 104 of the information system 140 publishes its subset of some higher global model to the information system 201. At the information system 201, the proxy integration agent 208 publishes this subset to the information system 201. The user interface 202 at the information system 201 can then access data at the information system 150 by querying the proxy integration agent 208, which pass the query onto the local integration agents such as the first and second integration agents 106 and 108. Preferably, the proxy integration agent 208 acts just like the integration agent 206 at the information system 201 and acts just like the user interface 102 at the information system 150. The proxy integration agent 208 acts as a pure pass-through or performs all the same mappings that a standard integration agent such as the third integration agent 206 can.

[0037] Although the information system 201 is shown to include only the third integration agent 206, additional integration agents (not shown) may be added to the information system 201 without departing from the true spirit of the present invention. Such additional integration agents will have the same interactions with other components of the information system 201 as the third integration agent 206 has.

[0038] In FIG. 3, a flow diagram 300 depicts a high-level operation of the present invention. The flow diagram 300 will be described in reference to the information system 100 of FIG. 1A; however, the flow diagram 300 is also applicable similarly configured information system according to the present invention.

[0039] In step 306, a query is assigned to a first integration agent. In the information system 100, the user interface 102 assigns the query to the first integration agent 106. In step 308, one or more sub-queries are created from the query. If in step 308 no sub-query is created, then empty result is returned. However, in step 308, it is assumed that at least one sub-query is created for subsequent steps to be executed. In the information system 100, the first integration agent 106 creates the one or more sub-queries from the query.

[0040] In step 310, the one or more sub-queries are assigned to one or more specific integration agents that have access to information relating to the one or more sub-queries. In the information system 100, the first integration agent 106 assigns the one or more sub-queries to the one or more specific integration agents. For example, if the one or more sub-queries are available only from the first information source 126, the first integration agent 106 assigns the one or more sub-queries to the first integration agent 106 itself. If the one or more sub-queries are available only from the second information source 130, the first integration agent 106 assigns the one or more sub-queries to the second integration agent 108. If first and second sub-queries of the one or more sub-queries require access to the first and second information sources 126 and 130, respectively, then the first integration agent 106 assigns the first and second sub-queries to the first and second integration agents 106 and 108-, respectively.

[0041] In step 312, the one or more sub-queries are processed in the one or more specific integration agents. In the information system 100 of FIG. 1, for example, at least one of the first and second integration agents processes the one or more sub-queries. Specifically, if the one or more sub-queries are available only from the first information source 126, the first integration agent 106 processes the one or more sub-queries. If the one or more sub-queries are available only from the second information source 130, the second integration agent 106 processes the one or more sub-queries. If first and second sub-queries of the one or more sub-queries require access to the first and second information sources 126 and 130, respectively, then the first and second integration agents 106 and 108 process the first and second sub-queries, respectively.

[0042] Optionally, each of the one or more sub-queries is evaluated to determine whether a particular sub-query is a base query. A base query is defined herein as a query including a class having one or more sub-classes under the class. For example, a bird class has many sub-classes including bluebirds, robins, doves, sparrows, etc. When a user queries a base query including the bird class, the user may want to get results from all sub-classes such as a bluebird class, a robin class, and a dove class. In that case, the specific integration agent handling the base query can first perform the query for each sub-class under the base query and then combine the results. Preferably, a domain model includes information on the number and kind of sub-classes under a base query.

[0043] In step 314, the one or more specific integration agents provide the one or more sub-query results to the first integration agent. In step 316, the one or more sub-query results are integrated in the first integration agent to obtain one or more query results corresponding to the query.

[0044] As shown in the flow diagram 300 in general and in steps 306, 310, 314, and 316 in particular, the present invention provides peer-to-peer architecture among a plurality of integration agents. This peer-to-peer architecture has numerous advantages over conventional agent-based information systems. For example, there is no single point of failure, because any one of the plurality of integration agents may assume the role of the first integration agent as in steps 306, 310, 314, and 316.

[0045] It will be understood from the foregoing description that various modifications and changes may be made in the preferred embodiment of the present invention without departing from its true spirit. This description is intended for purposes of illustration only and should not be construed in a limiting sense. The scope of this invention should be limited only by the language of the following claims. 

1. An information system for retrieving information from one or more information sources in response to a query and integrating the information in accordance with a domain model, the query being based upon the domain model, the system being based upon a computer network having one or more computer systems in communication with one another, the information system comprising: (a) a model agent residing in at least one of the one or more computer systems, the model agent having access to the domain model; and (b) a plurality of integration agents in communication with the model agent and residing in at least one of the one or more computer systems, the plurality of integration agents being in communication with one another in a peer-to-peer fashion, the plurality of integration agents having access to the one or more information sources, the plurality of integration agents publishing publication information to the model agent, the publication information including information on which portion of the domain model each of the plurality of integration agents has access to, the model agent providing the publication information to the plurality of integration agents such that the plurality of integration agents share the publication information among themselves through the model agent, the plurality of integration agents including at least a first integration agent, wherein the first integration agent receives the query, retrieves query results corresponding to the query from the one or more information sources through at least one of the plurality of integration agents, and integrates the query results.
 2. An information system for retrieving information from one or more information sources and integrating the information in accordance with a domain model, the system being based upon a computer network having one or more computer systems in communication with one another, the information system comprising: (a) a user interface residing in and accessible from at least one of the one or more computer systems for receiving one or more user inputs; (b) a model agent in communication with the user interface and residing in at least one of the one or more computer systems, the model agent having access to the domain model, wherein the user interface creates a query based upon the one or more user inputs and the domain model; and (c) a plurality of integration agents in communication with the user interface and the model agent and residing in at least one of the one or more computer systems, the plurality of integration agents being in communication with one another in a peer-to-peer fashion, the plurality of integration agents having access to the one or more information sources, the plurality of integration agents publishing publication information to the model agent, the publication information including information on which portion of the domain model each of the plurality of integration agents has access to, the model agent providing the publication information to the plurality of integration agents such that the plurality of integration agents share the publication information among themselves through the model agent, the plurality of integration agents including at least a first integration agent, wherein the first integration agent receives the query from the user interface, retrieves query results corresponding to the query from the one or more information sources through at least one of the plurality of integration agents, integrates the query results, and sends the query results to the user interface.
 3. The information system of claim 2, wherein the first integration agent creates one or more sub-queries from the query, assigns the one or more sub-queries to at least one of the plurality of integration agents based upon the publication information, retrieves one or more sub-query results corresponding to the one or more sub-queries from the one or more information sources through the at least one of the plurality of integration agents, integrates the one or more sub-query results to create one or more query results in accordance with the domain model, and sends the one or more query results to the user interface.
 4. The information system of claim 2, wherein the domain model includes a plurality of classes and one or more relations among the plurality of classes, each class having one or more attributes.
 5. The information system of claim 2, wherein the query results have inconsistent data formats provided by the information sources from which the query results retrieved, and wherein each of the plurality of integration agents has a means for mapping the inconsistent data formats of the query results into a consistent data format in accordance with the domain model.
 6. The information system of claim 5, wherein the means for mapping the inconsistent data formats of the query results into a consistent data format in accordance with the domain model further comprises: a value mapping means; a transformation means; and a function conversion means.
 7. The information system of claim 2, further comprising a security agent in communication with the user interface and the plurality of integration agents and residing in at least one of the computer systems, the security agent having access to a security database that defines users and their roles, wherein the user interface and the plurality of integration agents register with the security agent for security updates.
 8. An information system for retrieving information from one or more information sources and integrating the information in accordance with a first domain model, the system being based upon a computer network having one or more computer systems in communication with one another, the information system comprising: (a) a user interface residing in and accessible from at least one of the one or more computer systems for receiving one or more user inputs; (b) a first model agent in communication with the user interface and residing in at least one of the one or more computer systems, the first model agent having access to the first domain model, wherein the user interface creates a query based upon the one or more user inputs and the first domain model; (c) a first plurality of integration agents in communication with the user interface and the first model agent and residing in at least one of the one or more computer systems, the first plurality of integration agents being in communication with one another in a peer-to-peer fashion, the first plurality of integration agents having access to the one or more information sources, the first plurality of integration agents publishing first publication information to the first model agent, the first publication information including information on which portion of the first domain model each of the first plurality of integration agents has access to, the first model agent providing the publication information to the first plurality of integration agents such that the first plurality of integration agents share the first publication information among themselves through the first model agent, the first plurality of integration agents including at least first and second integration agents; (d) a second model agent in communication with the second integration agent and residing in at least one of the one or more computer systems, the second model agent having access to a second domain model; and (e) a second plurality of integration agents in communication with the second integration agent and the second model agent and residing in at least one of the one or more computer systems, the second plurality of integration agents being in communication with one another in a peer-to-peer fashion, the second plurality of integration agents having access to the one or more information sources, the second plurality of integration agents publishing second publication information to the second model agent, the second publication information including information on which portion of the second domain model each of the second plurality of integration agents has access to, the second model agent providing the second publication information to the second plurality of integration agents such that the second plurality of integration agents share the second publication information among themselves through the second model agent, wherein the first integration agent receives the query from the user interface, retrieves query results corresponding to the query from the one or more information sources through the first and second pluralities of integration agents, integrates the query results, and sends the query results to the user interface.
 9. The information system of claim 8, wherein the first integration agent creates one or more sub-queries including at least a first sub-query from the query and assigns at least the first sub-query to the second integration agent based upon the first publication information, and wherein the second integration agent assigns the first sub-query to at least one of the second plurality of integration agents based upon the second publication information, retrieves one or more sub-query results corresponding to the one or more sub-queries from the one or more information sources through at least the second integration agent, integrates the one or more sub-query results to create one or more query results in accordance with the first domain model, and sends the one or more query results to the user interface, and wherein the second integration agent
 10. The information system of claim 8, wherein the first domain model includes a plurality of classes and one or more relations among the plurality of classes, each class having one or more attributes.
 11. The information system of claim 8, wherein the query results have inconsistent data formats provided by the one or more information sources from which the query results retrieved, wherein each of the first plurality of integration agents has a means for mapping the inconsistent data formats of the query results into a consistent data format in accordance with the first domain model, and wherein each of the second plurality of integration agents has a means for mapping the inconsistent data formats of the query results into a consistent data format in accordance with the second domain model.
 12. The information system of claim 8, wherein the means for mapping the inconsistent data formats of the query results into a consistent data format in accordance with the second domain model further comprises: a value mapping means; a transformation means; and a function conversion means.
 13. The information system of claim 8, further comprising a security agent in communication with the user interface and the first plurality of integration agents and residing in at least one of the computer systems, the security agent having access to a security database that defines users and their roles, wherein the user interface and the first plurality of integration agents register with the security agent for security updates.
 14. A method for retrieving information from one or more information sources in response to a query and integrating the information in accordance with a domain model, the query being based upon the domain model, the one or more information sources being accessible from one or more integration agents, the method comprising the steps of: (a) assigning the query to a first integration agent; (b) creating one or more sub-queries based upon the query; (c) assigning the one or more sub-queries to one or more specific integration agents, the one or more specific integration agents having access to one or more specific information sources, the one or more specific information sources containing information relating to the one or more sub-queries; (d) processing the one or more sub-queries in the one or more specific integration agents to obtain one or more sub-query results; (e) providing the one or more sub-query results to the first integration agent; and (f) integrating the one or more sub-query results in the first integration agent to obtain one or more query results.
 15. The method of claim 14, wherein the step (d) comprises the steps of: (a) determining whether a first sub-query is a base query having a plurality of sub-classes; and (b) upon determining that a first sub-query is a base query, processing the first sub-query for at least part of the plurality of sub-classes.
 16. A computer program product for retrieving information from one or more information sources in response to a query and integrating the information in accordance with a domain model, the query being based upon the domain model, the one or more information sources being accessible from one or more integration agents, the computer program product having a medium with a computer program embodied thereon, the computer program product comprising: (a) computer program code for assigning the query to a first integration agent; (b) computer program code for creating one or more sub-queries based upon the query; (c) computer program code for assigning the one or more sub-queries to one or more specific integration agents, the one or more specific integration agents having access to one or more specific information sources, the one or more specific information sources containing information relating to the one or more sub-queries; (d) computer program code for processing the one or more sub-queries in the one or more specific integration agents to obtain one or more sub-query results; (e) computer program code for providing the one or more sub-query results to the first integration agent; and (f) computer program code for integrating the one or more sub-query results in the first integration agent to obtain one or more query results.
 17. The computer program product of claim 16, wherein the computer program code for processing the one or more sub-queries in the one or more specific integration agents to obtain one or more sub-query results further comprises: (a) computer program code for determining whether a first sub-query is a base query having a plurality of sub-classes; and (b) computer program code for, upon determining that a first sub-query is a base query, processing the first sub-query for at least part of the plurality of sub-classes. 